std::flat_multiset<Key,Compare,KeyContainer>::extract

 

C++

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Feature test macros (C++20)

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Technical specifications

Symbols index

External libraries

 

Containers library

Sequence

array (C++11)

vector

vector<bool>

inplace_vector (C++26)

deque

forward_list (C++11)

list

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set

multiset

map

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unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

Adaptors

stack

queue

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flat_set (C++23)

flat_multiset (C++23)

flat_map (C++23)

flat_multimap (C++23)

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span (C++20)

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std::flat_multiset

Member types

Member functions

flat_multiset::flat_multiset   flat_multiset::operator= Iterators flat_multiset::beginflat_multiset::cbegin flat_multiset::endflat_multiset::cend flat_multiset::rbeginflat_multiset::crbegin flat_multiset::rendflat_multiset::crend Capacity flat_multiset::size flat_multiset::max_size flat_multiset::empty Observers flat_multiset::key_comp flat_multiset::value_comp Modifiers flat_multiset::clear flat_multiset::insert flat_multiset::insert_range flat_multiset::emplace flat_multiset::emplace_hint flat_multiset::erase flat_multiset::swap flat_multiset::extract flat_multiset::replace Lookup flat_multiset::count flat_multiset::find flat_multiset::contains flat_multiset::equal_range flat_multiset::lower_bound flat_multiset::upper_bound

Non-member functions

swap(std::flat_multiset) erase_if(std::flat_multiset)    operator==operator<=>

Helper classes

uses_allocator<std::flat_multiset>

Tags

sorted_equivalent         sorted_equivalent_t

Deduction guides

 

container_type extract() &&;		(since C++23)

Extracts adapted container c. Equivalent to return std::move(c);.

After this operation *this is empty, even if an exception is thrown.

Parameters

(none)

Return value

std::move(c).

Complexity

Constant.

Example

Run this code

#include <cassert>
#include <flat_set>
#include <print>
#include <type_traits>
#include <vector>
 
int main()
{
    std::flat_multiset<int> set{1, 2, 3};
    const auto size = set.size();
 
    auto c = set.extract();
    assert(c.size() == size);
    assert(set.empty());
    assert(set.keys().empty());
    assert(set.values().empty());
 
    // The default keys container is std::vector:
    static_assert(std::is_same_v<decltype(c), std::vector<int>>);
 
    std::println("{}", c);
}

Output:

[1, 2, 3]

See also

replace

replaces the underlying container (public member function)